Mutual counterbalancing of tool holders of grinding machines



Dec. 29, 1931. SICHEL MUTUAL COUNTERBALANCING OF TOOL HOLDERS OF GRIND IQNG' MACHINES Filed Sept. 19, 1928 2 Sheets-Sheet 1 JNVENTOR.

L E o 5 l c H in.

Dec. 29, 1931. SICHEL' 1,839,002

MUTUAL COUNTERBALAN CING OF TOOL HOLDERS OF GRINDING MACHINES Filed Sept. 19, 1928 2 Sheets-Sheet 2 M v 6' 3,; Z6 [/6 I 1/4 W INVENTOR.

LEO SICHEIL.

Patented Dec. 29, 1931 Ap lication med: September 19,-1-928. -Sefia1 306,873.

'ancingby gravity, 'by'makingthe a would ne'cessftat e jfihe cdigrsftaiit aititip The reference numeral 10 indicates generally the working table of a grinding machine of any design and construction having apparatus 11 for operating the table, and a main base 12. A column 13 is rotatively mounted on the base 12 and has a co-axial shaft 14 provided with a gear 15 meshing with another gear 16 fixed on a shaft 17 rotatively mounted in the base and extending therefrom and provided on its free end with a hand wheel 18. This hand wheel may be turned for rotating the column 13.

A double tool arm 19, formed of separate sections 19 and 19 is slidably arranged on the column 13. The section 19 carries a tool head 21. The column 13 is provided with projecting ribs 22 engaging in cut-outs 22 formed in the tool sections for guiding the tool sections in their slidable movements. The tool sections are provided with ball bearing rollers 23 engaging against these projections 22 for protecting the latter against side alay.

1 Attached on the top of the column 13 is a guide member 24 and a main support leg 25 is slidably mounted in this guide member and held in fixed positions by a screw 26. The connection between the main support 25 and the guide 24 consists in a clove-tailed tongue and groove engagement 27. The main support leg 25 supports a pulley support bar 28 horizontally arranged. A large pulley 29 is rotatively mounted in the support bar on one side of the leg 25. Idler pulleys 30 and 30 are mounted on the support bar 28. A cable or chain 31 extends over these pulleys and has one of its ends connected with a gravity point bracket 42 attached on the arm section'l9 at its center of gravity and its other end connected with a gravity point bracket 42, attached on the arm section 19 at its center-of gravity.

The pulley 29 acts as a common point of suspension for the arm section. These arm sections are substantially balanced so that they may be easily moved, counterbalancing each other.

The gravity point bracket 42 consists of an attachment portion having an aperture 43 for receiving a fastening cap screw, as 44, and a toothed lower edge 45 for engaging a complementary recess in the arm sections, and an extension portion 46 which is provided with a dove-tailed groove 47. An eye member 48 is slidably arranged in this groove and capable of being fixed in desired positions by a set screw 49. The cable 31 is attached to the eye member 48. The brackets 42 may be set in various rotated positions as determined by the teeth 45.

Racks 32 are attached at the sides of the column 13 and mesh with gears 33 rotatively supported on the arm sections 19 and 19 integral with worm wheels 33 which in turn mesh with worms 34 fixed on shafts 35 and 35' rotatively mounted within the arm sections 19 and 19 respectively and extending therefrom. The hand wheels 36 and 36 are fixed on the free end of these shafts. Shafts 35 and 35 are secured in a pivoted bearing 35 to allow worms 34 to be moved out of engagement of worm wheels 33 whenever desired. The arm section 19 is formed with dovetailed tongues 37 engaged by support arms 38.

In operation of the device the tool head 20 is first arranged over the work table, and lowered by the operation of the hand wheel 36. Material to be worked upon is secured on the work table 10 and the apparatus 11 i operated for moving the work material while engaged with the tool head. Uponcompletion of the work with this tool head the section 19 may be raised. It is pointed out that the arm section 19 counterbalances arm section 19 for ease in raising either of these sections.

' The hand wheel 18' is then operated for rotating the column through an angle of 180 degrees. Then the hand wheel 36 may be operated for lowering the arm section 19 against the work on the work table. Various tools may be engaged within the tool heads and this may affect the centers of gravity of the arm sections. For this reason the eye members 48 may be moved to the new gravity positions and the main support leg 25 may be adjusted to a new position for changing the common point of suspension. The pulley support bar 28 is firmly held by auxiliary braces 39acting against the column 13. These braces may be fixed in desired positions by screws acting in slots 40 I It is also obvious that the counterbalancing by means of a chain or rope is only an example shown to illustrate the principal of the device and other forms of mechanism such as for instance beams, knife; points, universal joints or other means might be interposed for securing a counterbalancing and sliding along the vertical column 13 of the two tool support arms without in the least detracting from the character of the invention. 1 It is likewise immaterial to the character of the invention how many grinding heads are carried on each of'the sections. It is furthermore immaterial which form is given to the vertical column 13 as well as by which means the arm sections are given their sliding or positioning means along the column.

While I have shown and described the preferred embodiment of my invention, it is to:

be understood that I do not limit myself to the precise'construction herein disclosed and the right is reserved to all changes and modi-' fications coming within the scope of the in vention as defined in the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is p l. A device of the class described, comprising a base, a Work table mounted thereon, a column vertically .supported on the base, a pair of arm sections slidably'mounted on the column, tool heads supported on the said arm sections, and a means for counterbalancing one of the arm sections against the other.

2. A device of the class described, comprising a base, a Work table mounted thereon a column verticall su )orted on the.

base, a pair of arm sections slidably mounted on the column, tool heads supported on the said arm sections, and a means for counterbalancing one of the arm sections against the other consisting of a flexible member connected between the centers of gravityof the arm sections and m-ovably supported at a common point of suspension.

3. A device of the class described, comp -ising a base, a Work table mounted thereon, a column vertically supported on the base, a pair of arm sections slidably mounted on the column, tool heads supported on the said arm sections, and a means for counterbalancing one of the arm sections against the other consisting of a. flexible member connected between the centers of gravity of the arm sections and movably supported at a common point of suspension, and a means of changing the positionof the said common point of suspension for rebalancing the arm sections after tools are engaged in the said tool heads. v

e. A device of the class described, comprising a base, a Work table mounted thereon, a column vertically supported on the base and arranged for rotation, a pair of arm sections slidably mounted on the column, tool heads supported on the said arm sections, and a means for counterbalancing one of the arm sections against the other consisting of a flexible member connected between the centers of gravity of the arm sections and movably supported at a common point of suspension, and a means of changing the position of the said common point of suspension for rebalancing the arm sections after tools are engaged in the said tool heads, said latter means comprising a horizontal support bar adjustably mounted on said column and supporting a central large pulley and end idler pulleys, and said flexible member engaging over said pulleys.

5. A device of the class described, comprising a base, a Work table mounted'thereon, a column vertically supported on the base and arranged for rotation, a pair of arm sections slidably mounted on the column, tool heads supported on the said arm sections, and a means for counterbalancing one of the arm sections against the other consisting of a flexible member connected between the cenlatter means comprising a horizontal support bar adjustably, mounted on said column, and

supporting pulleys, and said flexible meinher ellg l gll lg over "said pulle s. i

.6. A device of;tl1e"class described, comprising abas'e, a 'ivork table mounted thereon, a column vertically supported on the base and arranged for rotation, a pair of arm sections slidably mounted on the column, tool heads supported on the said arm sections, and a means for counterbalancing one of the arm sections against the other consisting of a flexible member connected between the centers of gravity of the arm sections and movably supported at a common point of suspension, and a means of changing the position of the said common point of suspension for rebalancing the arm sections after tools are engaged in the said tool heads, said latter means comprising a horizontal support bar adj ustably mounted on said column and supporting'pulleys, said flexible members engaging over said pulleys, and reinforcing brackets'attached to the ends of the support bar and movably mounted on the column.

7 A device of the class described, comprising a base, a Work table mounted thereon,

a column vertically supported on the base;

and arranged for rotation, a pair of arm'sections slidably mounted on the column, tool heads supported on the said arm sections, and a means for counterbalancing one of the arm sections against the other consisting of i a flexible member connected betweenthe centers of gravity of the arm sections and movably supported at a common point of suspension, and a means of changing the po sition of the said common point of suspension for rebalancingt-he arm sections after tools are engaged in the said tool'heads, said latter means comprising a horizontal support bar adjustably mounted on said column and supporting pulleys, said flexible member engaging over said pulleys, said adjustable mounting comprising a guide member attached on saidcolumn, and a support leg attached to said-support bar and slidably movable insaid guide member.

8. In a device of the class described, a Work table, a column supported in the vicinity of the Work table, a pair of arm sections slidably supported upon said column, tool heads supported on said arm sections and engageable With Work on said Work table, and means for causing the tool heads to counterbalance each other so that one of thesaid tool heads may be easily drawn into an operative position upon moving the other to an inoperative position.

9. In a device of the class described, a work table, a column supported in the vicinity of the Work table, a pair of arm sections slidably supported upon said column, tool heads supported on said arm sections and engageable with Work on said tool heads in the opposite direction to the other and causing the tool heads to counterbalance each other so that one of the said tool heads may be easily drawn into an operative position upon moving the other to an inoperative position.

In testimony whereof I have afiixed my signature.

LEO SICHEL. 

